From: Emilio G. Cota <cota@braap.org>
Date: Sun, 19 Aug 2018 09:13:25 +0000 (-0400)
Subject: rcu_queue: use atomic_set in QLIST_REMOVE_RCU
X-Git-Tag: v3.1.0-rc0~119^2~33
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c177e0bf063659427874bf78236a762b5f040546;p=thirdparty%2Fqemu.git

rcu_queue: use atomic_set in QLIST_REMOVE_RCU

To avoid undefined behaviour.

Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20180819091335.22863-2-cota@braap.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/include/qemu/rcu_queue.h b/include/qemu/rcu_queue.h
index 01be77407ba..dd7b3be043e 100644
--- a/include/qemu/rcu_queue.h
+++ b/include/qemu/rcu_queue.h
@@ -112,7 +112,7 @@ extern "C" {
        (elm)->field.le_next->field.le_prev =        \
         (elm)->field.le_prev;                       \
     }                                               \
-    *(elm)->field.le_prev =  (elm)->field.le_next;  \
+    atomic_set((elm)->field.le_prev, (elm)->field.le_next); \
 } while (/*CONSTCOND*/0)
 
 /* List traversal must occur within an RCU critical section.  */